Study of a Toposequence of West Mayo-Kani Soils (Far North Cameroon)

Abstract

The soils of Gadas, object of the present study, are identified on the macromorphological, physico-chemical level and the indices of erodibility are related to their physico-chemical properties. The physico-chemical analyzes were carried out by standard methods. The macromorphological analysis of a toposequence made it possible to identify five types of soils: the lithosols which occupy the high zones of the landscape, the colluvial soils (arenosols, regosols) which are located high on the piedmont, alluvial soils (fluvisols) which are located at the bottom of the slope in the alluvial plain and are the most extensive, topomorphic vertisols, and brown soils formed on granite are located either between a colluvial soil and alluvial soil. Physico-chemical analyzes of the soils of Gadas show that these soils are weakly acidic to neutral, sandy to sandy-clayey, saturated, low in nitrogen and organic matter and characterized by average proportions of exchangeable bases. The study of soil erodibility, based on the use of erodibility indices, showed that alluvial soils and brown soils formed on granites are the most susceptible to erosion, whereas vertisols and colluvial soils are the least vulnerable to erosion.